This invention is directed to a remote computer monitor controller and more particularly to a method and device to control multiple computer displays with only one personal computer.
The vast majority of personal computers (PCs) include a video monitor display. Monitors are used to communicate information to the operator of the PC, such as displaying the text in a word processing application or a graph or chart showing data. Computer monitors are typically cathode ray tubes but can also be flat panel displays, such as liquid crystal or field emission displays.
A functional diagram of a typical personal computer system 10 having one associated monitor is shown in FIG. 1. A CPU 20, such as an Intel Pentium(copyright) processor or a K6 processor from Advanced Micro Devices, Inc. is linked to a local bus 22. Also coupled to the local bus 22 is a memory controller 24 that controls level-2 cache memory 26 and dynamic random access memory (DRAM) 28. Also coupled to the local bus 22 is a local bus/PCI bus bridge 30. This bus bridge 30 links the local bus 22 with a peripheral control interface (PCI) bus 32.
Attached to the PCI bus 32 are controllers of their own buses, such as an IDE controller 60 and a SCSI controller 62. These controllers are used to couple devices, such as hard drives, CD-ROM drives, DVD ROM drives, scanners, and other peripheral devices to the PCI bus 32 and ultimately to the CPU 20. The PCI bus 32 also contains PCI slots 34, 36, 38 which act as receptacles for xe2x80x9ccardsxe2x80x9d. These cards provide a mechanism by which external devices can communicate directly with the PCI bus 32 of the computer system 10. For instance as shown in FIG. 1, a video card 44 is installed into the PCI slot 34. The video card 44 contains circuitry that allows the CPU 20 to communicate to a computer monitor 48 by passing electrical signals over the PCI bus 32. The video card 44 senses these signals placed on the PCI bus 32 by the CPU 20 and converts them into analog signals for use by the monitor 48. A video cable 68 carries signals from the video card 44 to the monitor 48.
A network interface card (NIC) 46 is installed in the PCI slot 36 of the computer system 10. The NIC 46 contains circuitry that allows the computer system 10 to communicate to a computer network over a network cable 50. The network cable 50 plugs directly into the NIC 46. The NIC 46 is chosen to be compatible with a particular type of network to which the computer system 10 is to be connected, such as Token-Ring or Ethernet.
A PCI/ISA bus bridge 70 couples the PCI bus 32 to an Industry Standard Architecture (ISA) bus 72. Similar to the PCI bus 32, the ISA bus 72 has a number of slots, 92, 94, 96, 98, that are used to accept cards that communicate with the computer system 10 over the ISA bus 72. The ISA slots act as a separate physical extension to a corresponding number of XT slots, 82, 84, 86, and 88, respectively. Cards that fill one of the ISA slots also fill the corresponding XT slot. For example, the computer system 10 has an I/O adapter card 66 that sits in both XT slot 82 and ISA slot 92. All ISA cards must utilize ISA and XT slots while XT cards may only utilize XT slots. Cards placed in either the XT or ISA slots communicate with the CPU 20 via the ISA bus 72 through the bus bridges 70 and 30. Also coupled to the PCI/ISA bus bridge 70 are other components necessary for proper operation of the computer system 10, such as a ROM Bios 74, a real-time clock 76, and a keyboard/mouse controller 78.
In order to have more than one monitor 48 coupled to the computer system 10, an additional or different type of video card must be plugged into one of the PCI slots. Some operating systems, such as Microsoft Windows 98(copyright), allow more than one monitor 48 to be operational at one time. However, the number of monitors 48 is dictated by the number of available PCI slots 34, 36, 38 available in the computer system 10. In the computer system 10 illustrated in FIG. 1, only one additional computer monitor 48 could be added, by inserting another video card (not shown) into the only open PCI slot, 38. Some newer video cards operate on an Accelerated Graphics Port (AGP) bus, which provides a faster data path between an AGP video card (not shown) and the CPU 20. Typically only one slot is provided to the AGP bus, thereby limiting the number of AGP video cards per system to one.
Some companies, such as Appian Graphics of Redmond, Washington, produce video cards that can display different images on multiple monitors from one video card. However, the number of monitors driven from one video card is limited to a fairly low number, such as 2 or 4. Additionally, Dexon Systems Limited of Great Britain produces hardware that allows multiple monitors to be attached to a computer system. However, in their system, the monitors are stacked on top of and next to one another in a matrix of rows and columns. The product allows this matrix of computer monitors to display only a single image, with every monitor showing a small portion of the total image.
U.S. Pat. No. 3,623,067 to Deal, Jr. teaches a master panel control unit for coordinating panels in a number of debarkation areas. However, each master panel must be uniquely associate with another panel in another area. Further, the panels of Deal, Jr. cannot contain images, but only numbers and letters in xe2x80x9cilluminated lamps behind ground glass plates.xe2x80x9d
What is needed, therefore, is a device that allows images to be shown on as many computer displays coupled to a computer system as desired, without being limited by the number of available open slots in a bus or the number of displays driven by one video card.
According to one aspect of the present invention, a remote monitor controller includes an input module that receives a stream of digital data. The input module is linked to a microcontroller that converts the digital data into image display data, which is stored in a video RAM module. An output module converts the image display data stored in video RAM into analog signals that are sent to a display unit where the image is shown.
According to another aspect of the present invention, image data is provided to at least one computer display. First data representing an image is generated by a generating device, such as a personal computer. Then the data is addressed to one or more of the display units and sent along a computer network to the associate display units. At the addressed display unit, the image data is retrieved from the computer network, converted and stored as a locally-stored image. The locally-stored image is then shown on the display unit until another image is stored.